Hydraulic pruning attachment

ABSTRACT

A saw attachment for pruning trees, shrubs and undergrowth that can be used on a hydraulic vehicle, having auxiliary line connections for accepting attachments. The attachment has cutting blades located at the ends of a swing arm, which is mounted on a plate capable of holding a single, fixed angle of orientation from 0° to 90° with respect to the imaginary plane of the direction of travel of the vehicle. Depending on the type of host vehicle on which the attachment is used, the attachment can be mounted using either a connector plate or an articulated extension arm.

FIELD OF THE INVENTION

This invention relates to an apparatus for use with landscapingequipment and, more specifically, to a pruning attachment that may beconnected to working end of a hydraulic machine, such as a front-endloader or a back-hoe, that has auxiliary hydraulic line connections forsuch attachments.

BACKGROUND OF THE INVENTION

Existing industrial hedgers and cutting tools are typically singlepurpose vehicles that include either a single cutting blade or aplurality of cutting blades that are fixed to either a stationary or arotating cutting blade arm. These hedgers operate in a single or at mosttwo planes. As a result, such hedgers are limited as to the types ofoperations they can perform. Where multiple operations are contemplated,the operator is required to change either an attachment or theorientation of the blades. For example, U.S. Pat. No. 2,404,655 toRandall, dated Jul. 23, 1946, describes a Machine for Felling Trees.This machine provides two saws, one mounted horizontally and the othermounted vertically. The horizontal blade is used for felling trees,whereas the vertical blade is used for cutting the felled trees intologs. The two blades are not mounted on the same bearing member andcannot be used concurrently.

A Dec. 11, 1951 patent issued to Miller et al. for Tractor Mounted BrushSaw, U.S. Pat. No. 2,577,906 identifies a machine having two or moresaws mounted on a frame positioned at the front end of a tractor. Thesaws are operated by individual power units, so that the speed of eachcan be varied independently.

Similarly, U.S. Pat. No. 2,624,380 for Brush Saw to L. N. Haynes, datedJan. 6, 1953, has two saw blades that are carried forward of the frontend of a tractor. Although each saw blade assembly may be tiltedupwardly from a horizontal position, there appears to be no structurewhich would allow for the blades to be positioned alongside the tractor.

Vertically-Adjustable Tree-Felling Tractor Mounted Saw was issued toRyals on Dec. 1, 1953, as U.S. Pat. No. 2,661,035. This inventiondescribes a saw blade apparatus attached to the front end of a tractor.The assembly includes a frame that allows the single blade to be raisedor lowered and to be moved sideways from one front corner of the tractorto the opposite front corner. The structure of this invention does notpermit the blade to be moved to the side of the tractor or to be tiltedfrom the horizontal to the vertical.

Whitmore obtained U.S. Pat. No. 2,940,486 on Jun. 14, 1960, for PruningApparatus. This invention is permanently mounted, and is not adapted asan attachment. The Whitmore machine also appears not to be capable oflowering the saw blade bearing arm to ground level with the blades in ahorizontal orientation. The downwardly movement of the saw blade arm islimited by the height above ground of the trailer frame. Accordingly,this machine does not appear capable of orienting the saws so that theyare at ground level.

U.S. Pat. No. 3,157,016 was granted on Nov. 17, 1964, to Leydig et al.for a Tree Topper With Reciprocating Cutter Boom. This machine, includesan articulated boom which carries a cutter arm having multiple sawblades. The cutter arm is raised and extended from the front of aself-propelled vehicle, such as a tractor, however the cutting apparatusis not an add-on that can be adapted to various vehicles. Additionally,in the Leydig invention the cutting apparatus is carried on the front ofthe vehicle and, is not borne laterally on the vehicle and thus would beunable to prune the lower sides of hedges.

A second patent was issued on Jul. 6, 1965, to Leydig as U.S. Pat. No.3,192,695 for Tree Trimming Machine Or the Like. This machine issomewhat different from that of the previous Leydig patent, but is alsoa dedicated piece of equipment rather than an attachment adaptable tovarious vehicles. The cutter arm in this machine is capable of trimmingbushes in a direction lateral to the direction of travel of the machineon the side of the vehicle. The cutting arm may also be tilted, butappears incapable of being extended to ground level.

A third patent to Leydig et al., U.S. Pat. No. 3,487,615 dated Jan. 6,1970 is for Double-Boom Hedger. This is an interesting machine in whichthe vehicle resembles a bulldozer having two cutting arms connectedforward of the vehicle. The cutting arms hydraulically extend upwardly,and may also be deployed laterally from the vehicle; however, thecutting arms cannot be tilted sufficiently to reach ground level.

U.S. Pat. No. 4,592,398 was issued on Jun. 3, 1986, to Golob et al. forContinuous Tree Harvestor [sic]. This invention appears directed to thecutting, harvesting and bundling of small trees such as Christmas trees.The cutting apparatus is positioned along the front of the vehicle andat relatively close to ground level but does not have the capability ofbeing turned sideways relative to the vehicle.

Grant received U.S. Pat. No. 5,430,999 on Jul. 11, 1995, for TreeTrimming And Pruning Machine. This invention provides a cutting armbearing multiple saw blades. The cutting arm is extendable hydraulicallyto reach the tops of trees and the blades may be turned so as to beoriented horizontally, However this machine cannot cut a vertical swathbeside the vehicle as the hydraulic arm extends only directly ahead ofthe vehicle and not beside it.

Industrial Vehicle With Adjustable Boom Members to Edwards, U.S. Pat.No. 6,085,505, dated Jul. 11, 2000, describes a machine that isdedicated to cutting and is not an attachment for a pre-existingvehicle. Saw blades are borne on a hydraulically extendable boom and thecutting arm includes a pivot linkage that allows the blades to be turnedfrom a vertical alignment to a horizontal alignment allowing the toppingof trees.

SUMMARY OF THE INVENTION

With the foregoing in mind, the present invention advantageouslyprovides a saw attachment, rather than a dedicated vehicle, havingcutting blades mounted on an elongated cross-arm member that may beoriented horizontally, vertically and at any angle therebetween relativeto the direction of travel so that topping, trimming, cutting, and brushremoval may all be accomplished using a single piece of equipment thatcan be attached to the working end of a front-end loader, a back-hoe orany other piece of industrial machinery, referred to herein as a hostvehicle. In the preferred embodiment, the host vehicle will haveconnections for accepting hydraulic attachments.

The invention commonly includes a base plate on which is mounted thebase unit of a pivot plate hydraulic cylinder, the base plate ispivotally connected to a pivot plate to which a working end of the pivotplate hydraulic cylinder is also connected. Attached to the underside ofthe pivot plate is a swing arm which is carried on a rotatableconnection, such as a pivot or axle, so that it is capable of turningthrough 180° of arc relative to the connection. The swing arm has ateither end along its lengthwise extent a circular saw blade that is alsoborne on a mechanical rotatable connection that is driven by a belt orchain-drive mechanism located inside the swing arm that rotates thecircular saw blades. The mechanism is driven by a swing arm motormounted on the pivot plate and hydraulically connected to the rotatableconnection of the swing arm. However, those skilled in the art willrecognize that the invention could work equally well with an electricalswing arm motor driven from connections to the battery of the hostvehicle.

In a first embodiment this saw attachment assembly is connect able to ahydraulic host vehicle, such as a Bob Cat™ or a front-end loader, byreplacing the bucket of those vehicles with an extension assembly thatis slidably connected to the connector plate. The extension assembly hasa hydraulic cylinder actuator that can be used to slide the supportplate to the side of the connection plate. This attachment will properlybe completed by the addition of a safety guard that attaches to the armon either blade, or across the length of the entire arm.

In an alternative embodiment, the base plate, pivot plate and swing armhaving two circular saw blades are mounted laterally at the terminal endof an articulated, hydraulic extension arm. The hydraulic extension armis attached to the working end of a back-hoe in place of its shovel.

In the specification there have been disclosed typical preferredembodiments of the invention, and although specific terms are employed,the terms are used in a descriptive sense only and not for purposes oflimitation. The invention has been described in some detail, but it willbe apparent that various modifications and changes can be made withinthe spirit and scope of the invention as described in the foregoingspecification and as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the features, advantages, and benefits of the present inventionhaving been stated, others will become apparent as the descriptionproceeds when taken in conjunction with the accompanying drawings,presented solely for exemplary purposes and not with intent to limit theinvention thereto, and in which:

FIG. 1 is a view of a front-end loader in which the saw attachment hasreplaced the bucket so that the saw attachment takes advantage of thefront-end loader's ability to raise the saw attachment to the height ofa tree's limbs, demonstrating how the attachment can be used to trim atree according to an embodiment of the present invention;

FIG. 2 is a view of a front-end loader to which the apparatus has beenattached showing the orientation of the saw attachment at ground levelto trim brush from underneath hedges according to an embodiment of thepresent invention;

FIG. 3 is a view illustrating how the components of a saw attachmentaccording to an embodiment of the present invention;

FIG. 4 is a view showing the movement of an hydraulic cylinder actuatorcauses an extension assembly to move laterally with respect to aconnector plate so that the proximity of the saw attachment to a hostvehicle is affected according to an embodiment of the present invention;

FIG. 5 is a view of the apparatus illustrating how the hydrauliccylinder residing on the support plate and pivot plate can be used toset the angle of a swing arm and saw blades from a horizontalorientation through 90 degrees to a vertical orientation according to anembodiment of the present invention;

FIG. 6 is a view of the apparatus showing how the swing arm can berotated through approximately 180° relative to its point of connectionaccording to an embodiment of the present invention;

FIG. 7 is a top-down view of the swing arm showing how a chain or beltdrive is used to rotate the circular saw blades about their point ofconnection according to an embodiment of the present invention;

FIG. 8 is an edge-on view showing how a chain or belt drives used torotate the circular saw blades are oriented about the rotatable point ofconnection within the swing arm according to an embodiment of thepresent invention;

FIG. 9 is a top-down view of the swing arm and the swing arm motorshowing how a chain or belt drive is used to rotate the swing arm aboutits point of connection according to an embodiment of the presentinvention;

FIG. 10 is an edge-on view of the swing arm motor showing how a chain orbelt drives used to rotate the circular saw blades are oriented aboutthe point of connection within the swing arm according to an embodimentof the present invention; and

FIG. 11 is a view of an alternative embodiment showing back-hoe havingan articulated arm attachment and illustrating how the motor and swingarm are oriented to a lateral point of connection thereon according toan embodiment of the present invention.

FIG. 12 is a view of the saw attachment of FIG. 1 mounted on a front-endloader and having the saw blades being rotated by the swing arm to trimthe vertical side of a hedge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. Unless otherwise defined, technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionpertains. Although methods and materials similar or equivalent to thosedescribed herein can be used in the practice or testing of the presentinvention, suitable methods and materials are described below. Allpublications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety. Incase of conflict, the present specification, including any definitions,will control. In addition, the materials, methods and examples given areillustrative in nature only and not intended to be limiting.Accordingly, this invention may be embodied in many different forms andshould not be construed as limited to the illustrated embodiments setforth herein. Rather, these illustrated embodiments are provided solelyfor exemplary purposes so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art. Other features and advantages of the invention willbe apparent from the following detailed description, and from theclaims.

FIG. 1 depicts a saw attachment 10 that can be used on a host vehicle,such as a tractor, front-end loader, or Bob Cat™, or any other piece ofhydraulically operated equipment having connections for suchattachments. As shown in FIG. 1, the standard bucket attachment of thehost vehicle is replaced by a saw attachment 10. FIG. 2 provides a viewof a host vehicle showing how the saw attachment 10 is used at groundlevel to cut down a small tree or to remove brush or undergrowth.

A view showing the elements of the saw attachment 10 is provided in FIG.3, which shows a connector plate 14 that may be substituted in place ofa bucket attachment on the front end of a host vehicle. Extendingoutwardly along an imaginary plane substantially perpendicular to theconnector plate 14 and horizontal with respect to the host vehicle is asupport plate 16. An extension assembly 18 slidably connects the supportplate 16 to the connector plate 14, and has a hydraulic cylinderactuator 20 operable to slide said support plate 16 laterally outwardfrom the host vehicle relative to said connector plate 14. FIG. 4further illustrates that when the hydraulic cylinder actuator 20 isengaged, the hydraulic extension assembly 18 is moved laterally out fromthe connector plate 14, which has the affect of moving the entire sawattachment away from or into an imaginary plane defined by the directionof travel of a host vehicle.

Along a lateral periphery of the support plate 16 is a pivot plate 22that is connected to the support plate by a pivot or hinge 24. A pivotplate hydraulic cylinder 26 is mounted at a base end 28 to the supportplate and is mounted at its working end 30 to the pivot plate 22. Thepivot plate hydraulic cylinder 26 permits the pivot plate 22 to be movedthrough 90° of arc relative to the support plate 16 so that theorientation of a swing arm 12 mounted to the lower side of the pivotplate 22 may be oriented at the proper angle for the work to beperformed. As illustrated in FIG. 5, the movement of the pivot plate 22is controlled by the compression of the pivot plate hydraulic cylinder26 so that the pivot plate may be held at a single, fixed angle, eitherhorizontal, vertical or at any angle in between, during operation. Thisallows the saw blades to travel at a uniform cutting height with respectto the ground, thus maintaining a uniform cutting.

Mounted to a lower side of the pivot plate 22 is a swing arm 12 having alengthwise extent and two spaced apart ends 34, 36. The swing arm 12 isborne on a rotatable connection 38 to the lower side of the pivot plate32 so that the swing arm may rotate through at least approximately 180°of arc relative to the connection 38, as depicted in FIG. 6. Therotation of the swing arm is driven by a swing arm motor 40 that useshydraulic fluid connections 41 from the host vehicle to activate themotor, as shown in FIG. 7.

Each of two circular saw blades 42, 44 is carried on its own individualrotatable connection 46, 48 located at each end 34, 36 of the swing arm12. These saw blades 42, 44 are operated by at least one belt or chaindrive 50, 51 located within the swing arm. Each belt 50, 51 is driven bya saw blade motor 52 mounted on the pivot plate 32 adjacent the swingarm motor 40. The compressive force is provided to the saw blade motor52 via hydraulic fluid connections 56 from the host vehicle in a manneridentical to the connections 41 of the swing arm motor 40 to the hostvehicle. Each belt is attached about the rotatable connection 46, 48 atthe ends 34, 36 of the swing arm 12 and in the center about a beltrotatable connection 58, such as gears, mounted adjacent the swing armrotatable connection 38, as shown in FIG. 8. The saw blade motor 52drives a linkage belt 54 attached between the saw blade motor 52 and thebelt rotatable connection 58. The movement of the linkage belt 54 causethe belts 50, 51 mounted about the belt rotatable connection 58 and theindividual saw rotatable connections 46, 48 to turn, causing each sawblade 42, 44 to spin about its own rotatable connection 46, 48. Whilethis embodiment also shown in FIG. 12 represents that preferred by theinventor, those skilled in the art will recognize that for someapplications in the related arts, multiple saw blades, and saw blades ofdifferent geometries may be desirable.

FIG. 11 depicts an alternative embodiment of the saw attachment 10 isattached to a back-hoe using an articulated arm attachment 60, ratherthan a connector plate 14 and an extension assembly 18, as discussed inthe previous embodiment. FIG. 11 illustrates that the swing arm 12 isconnected to the articulated arm 60 on a rotatable connection 62 that ispositioned laterally to the longitudinal axis of the articulatedhydraulic arm 60 near a terminal end of that arm 64. Absent in thisembodiment is the connector plate 14, and the support plate 16. Thefunctions of these components are instead performed by the articulatedhydraulic arm 60, which can be used to set the orientation and height ofthe cutting blades mounted on the swing arm. The pivot plate 22 isreplaced by a motor housing 66, which a box capable of holding the swingarm motor 40 and the saw blade motor 52 and their associated hydraulicconnections 41 and 56, respectively. Operation of the swing arm 12, sawblades 42, 44, swing arm motor 40 and saw blade motor 56, and belts 50,51, and linkage belt 54, remain unchanged from the previous embodiment.

In the drawings and specification, there have been disclosed typicalpreferred embodiments of the invention, and although specific terms areemployed, the terms are used in a descriptive sense only and not forpurposes of limitation. The invention has been described in considerabledetail with specific reference to these illustrated embodiments. It willbe apparent, however, that various modifications and changes can be madewithin the spirit and scope of the invention as described in theforegoing specification and as defined in the appended claims.

1. A saw attachment for a vehicle capable of supporting hydraulicattachments, said saw attachment comprising: a connector plateconnectable to a working end of the vehicle; a support plate extendingoutwardly from said connector plate along an imaginary planeapproximately perpendicular thereto; a pivot plate pivotably connectedalong a lateral periphery of said support plate; a swing arm having alengthwise extent and two spaced apart ends, said swing arm borne onsaid pivot plate on a rotatable connection so as to rotate relative tothe connection; two saw blades, each connected adjacent an end of saidswing arm; a hydraulically actuated motor supported on said pivot plateand connected to actuate the rotatable connection of said swing arm andsaid two saw blades; a first hydraulic cylinder operably connectedbetween said support plate and said pivot plate to thereby pivotablyactuate said pivot plate relative to said support plate; and anextension assembly slidably connecting said support plate to saidconnector plate, said extension assembly having at least one hydrauliccylinder actuator operable to slide said support plate laterally outwardfrom the vehicle relative to said connector plate.
 2. The saw attachmentof claim 1, wherein said pivot plate is connected to said support plateby a hinge.
 3. The saw attachment of claim 1, wherein the vehicle is anindustrial or agricultural vehicle selected from a front-end loader, abackhoe, a tractor, a bulldozer, and a bobcat.
 4. The saw attachment ofclaim 1, wherein said two saw blades are circular blades.
 5. The sawattachment of claim 1, wherein the connection between said hydraulicallyactuated motor and said two circular saw blades is a belt.
 6. The sawattachment of claim 1, wherein the connection between said hydraulicallyactuated motor and said two circular saw blades is a chain.
 7. A sawattachment for a vehicle having a hydraulically operated arm, said sawattachment comprising: a connector plate connectable to a working end ofthe hydraulically operated arm; a support plate extending outwardly fromsaid connector plate along an imaginary plane approximatelyperpendicular thereto; a pivot plate pivotably connected along a lateralperiphery of said support plate; a swing arm having a lengthwise extentand two spaced apart ends, said swing arm borne on said pivot plate on arotatable connection so as to rotate relative to the connection; two sawblades, each connected adjacent an end of said swing arm; ahydraulically actuated motor supported on said pivot plate and connectedto actuate the rotatable connection of said swing arm and said two sawblades; a first hydraulic cylinder operably connected between saidsupport plate and said pivot plate to thereby pivotably actuate saidpivot plate relative to said support plate; and an extension assemblyslidably connecting said support plate to said connector plate, saidextension assembly having at least one hydraulic cylinder actuatoroperable to slide said support plate laterally outward from thehydraulically operated arm relative to said connector plate.
 8. The sawattachment of claim 7, wherein said pivot plate is connected to saidsupport plate by a hinge.
 9. The saw attachment of claim 7, wherein theconnection between said hydraulically actuated motor and said twocircular saw blades is a belt.
 10. The saw attachment of claim 7,wherein the connection between said hydraulically actuated motor andsaid two circular saw blades is a chain.
 11. The apparatus of claim 7,wherein said one or more cutting members are selected from a chainsawand a circular saw blade.